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Sunday, February 27, 2011

The German Winter is making place for Spring's first green, and our two lovely girls are now almost two months old. Lara and Gloria have outgrown the newborn diapers and we've sorted out the first set of clothes that got too tight. They have learned to suck on their fingers and are starting to focus on things. Since last week, Gloria is smiling generously while Lara prefers to stick out her tongue. At present they can neither grab nor hold any toys, and the only thing they seem to recognize are faces and milk bottles. They also haven't yet shown any intention of sleeping through the night

It has become apparent that the sisters are very different in character. Gloria is easily bored and wants to be entertained. Lara is content lying in her bed listening to music and playing with her fingers. Since neither Stefan nor I can recall the lyrics of children's songs and can't hold any tune anyway, the babies have an iPod player introducing them to essentials of German Culture. My favorite lullaby is clearly Kleine Taschenlampe Brenn (Glow, little flashlight) and the other day I caught Stefan humming La Le Lu while stuffing laundry into the machine. I've also rediscoverd forgotten childhood gems, such as Hey Wicky and Pippi Langstrumpf. Lara and Gloria both like Maja the Bee, but can't stand Captain Future.

The girls have made their first encounters with babysitters, and I am stunned by the variety of skin problems babies can have and by the amount of recommended alleged remedies. We meanwhile have a large selection of bottles, lotions and cremes for one or the other purpose that goes on this or that body part.

Meanwhile, I am still fighting with the health insurance. Every time I think I've finally filled out all forms and sent them all documents, I find another letter in our mailbox with another form or request for documents. The amount of paperwork that a pregnancy generates is simply amazing. The babies have also received their first mail ever: From the revenue office assigning them a tax number.

Tuesday, February 22, 2011

The German Defense Minister Karl-Theodor zu Guttenberg holds the title of Dr. jur. from the University in Bayreuth. He finished his thesis in 2006, at age 34, with more than 450 pages on the topic "Verfassung und Verfassungsvertrag: Konstitutionelle Entwicklungsstufen in den USA und der EU" (On the development of constitution in the USA and the EU). Guttenberg obtained the best possible grade, summa cum laude.

Two weeks ago, it turned out that big parts of his thesis were copied from other people's academic papers or newspaper articles. Since last week, one finds online a Wiki called GuttenPlag dedicated to collecting the copied paragraphs. The status is summarized in the below graphic (taken from mentioned Wiki):Marked in black are pages on which plagiarized paragraphs have been found. Red are pages on which copies from several sources have been found. White means nothing has been found and blue is the table of contents and reference list that is not included in the search.

This eerily reminds me of a dissertation thesis I read last year. While the presented research was original, big parts of the text introducing the topic and explaining the relevance of the study were exact copies from other people's published review articles or research papers, including footnotes and references. The original work was cited in the text, but nowhere was it clearly marked the text was essentially an unauthorized reprint. Confronted with the evidence for his generous copying, the student first pointed out that he had cited the original papers. Yet, for a proper citation half of the thesis would have had to appear in quotation marks. Commenting on zu Guttenberg's "work," Volker Rieble, an expert on plagiarism summarized the core problem (as quoted in this Zeit article):

"The reader is deceived in knowing that a particular paragraph, a particular part of the text, a particular thought, did not come from doctoral candidate zu Guttenberg but from somebody else. This is not in accordance with scientific standards."

So you're not done with putting a citation somewhere, you have to make clear to the reader what is the extend of your borrowing. On further inquiry, the candidate whose thesis I had read - not a native English speaker - said with heartwarming honesty he had started writing the text but then found the other authors had said it so much better and clearer that the reader would benefit from using their words. The thesis was withdrawn and replaced prior to the defense. The candidate passed - as I said, his research was fine. Zu Guttenberg, whose copying work was only noticed after his defense, now has to await the University of Bayreuth's decision on whether he will be allowed to keep his title.

I know several examples where physicists, including myself on more than one occasion, have found paragraphs from their papers reappear in other people's papers. While the source was quoted somewhere in the text, the copied paragraphs were not marked as quotation. In all cases I know of, the people copying others' texts were not native English speakers.

"Research carried out by academics at Beihang University in Beijing found a startling lack of understanding of plagiarism and academic misconduct, with both students and staff admitting that they knew "very little" or "had no idea" about the norms of scientific ethics. [U]p to 10 per cent of the students surveyed said that they thought copying work directly from the internet should not be considered bad practice."

"[M]any applicants borrowed phrases from the same free website... In 234 applications to study medicine [from 50,000 applications to study medicine, dentistry and veterinary science at the universities of Oxford and Cambridge], candidates wrote that it was “burning a hole in my pyjamas at age eight” that sparked their passion for the subject."

So much about individualism.

The reason this depresses me is that these young people willingly give up the offered possibility of personalizing their application. The alternative is being reduced to numbers and, eventually, being assessed by some measure for success.

So, evidently, copy and pasting others' texts is becoming ever more common, and many people at least claim to not know it's unethical not to properly cite ones' sources. Where does this get us? I am wondering now if not time will come when a scientist can assemble parts of his paper from already published articles - a motivation from there, some literature review from there, summary of the method from there, of course marked as quotation - and just add the relevant new equations, tables, and figures. Does everybody really have to write the always same introduction in his own words (and then plagiarize himself in further publications)?

Friday, February 18, 2011

In the very early universe matter was dense and hot. With the expansion of space, matter cooled down which eventually allowed for the formation of nuclei and later atoms, molecules and increasingly large structures. Atoms could be formed when the average energy of electrons decreased to a value so small that ionization became improbable - an event called recombination. Photons, which prior to recombination were scattered on the free electrons, could then travel almost undisturbed. This happened at a temperature of about 1 eV, or some thousand Kelvin. Due to the continuing expansion of the universe, the photons from that time became redshifted, but are still present today. Their temperature is now at 2.7 K, and they have become famous under the name Cosmic Microwave Background (CMB). The temperature fluctuations in the CMB carry information about the structure of matter at the time of the photons' decoupling from matter. WMAP has measured these temperature fluctuations with great accuracy. (We discussed the CMB and some of what we have learned from it here, here, here and most recently here.)

The photons that we are so used to rely on for "looking" do not allow us to learn anything about the early universe prior to recombination. But we can try to see by other means. Neutrinos are well known for being weakly interacting, which is why they are so difficult to detect. But that they interact only weakly also means neutrinos ceased to scatter on the hot matter in the early universe earlier than photons. This happens at the typical energy scale for the weak interaction, at about 1 MeV or 1010K, after which the scattering of neutrinos and anti-neutrinos to produce an electron-positron pair became very improbable and, briefly after this, nucleosynthesis took place. Today, the temperature of the cosmic neutrino background, CνB, is about 10-4 eV or 2 Kelvin* and it's all around us.

While we have not yet measured the absolute neutrino masses, but only have upper bounds, neutrino oscillations test for the differences of squares of masses. This allows us to conclude that at least some of the neutrino species must have cooled so much that their kinetic energy is smaller than their restmass, which means they are non-relativistic. This is interesting because these neutrinos will then clump in gravitational fields like that of our Milky way. As a consequence, the density of neutrinos on the path of planet Earth is roughly one to two orders of magnitude larger than the average density.

Still, these CνB neutrinos are very difficult to detect. But difficult is not impossible. Neutrino capture on tritium would, with some effort but presently available technology, yield a detection rate of maybe 10 CνB neutrinos per year [reference]. That would be enough to confirm the presence of the CνB, but to measure temperature fluctuations, with that procedure we'd probably have spend some million years doing nothing but gathering statistics, not to mention that tritium doesn't grow on trees. Alternative to tritium, it has recently been proposed to instead capture anti-neutrinos on Holmium, which, with some effort and some luck, might yield comparable detection rates. Direct detection of the CνB is the first step. Since the detection rate depends on the neutrino-density, it would not only confirm our theories about the creation of the neutrino-background, but give us information about the distribution of neutrinos in the gravitational field of our galaxy.

Sure, there's only so much you can learn from 10 neutrinos per year. But who knows what technological progress will bring? Half a century ago, the precision with which WMAP measured tiny fluctuations in a temperature that is tiny to begin with would have seemed a fantasy. Today it's fact. So here I am telling you that the CνB is out there, waiting for us to harvest the information it contains.

* It is (4/11)1/3 times the temperature of the CMB. The conversion factor is partly due to neutrinos being fermions while photons are bosons, and partly due to the photons gaining in density, and thus temperature, when electron-positron pairs annihilate to photons while the opposite reaction becomes increasingly improbable. When this happened, neutrinos had already decoupled.

Monday, February 14, 2011

A Brilliant DarknessThe Extraordinary Life and Mysterious Disappearance of Ettore Majorana, the Troubled Genius of the Nuclear Age

João MagueijoBasic Books (November 24, 2009)

The Italian theoretical physicist Ettore Majorana disappeared in 1938 at the age of 31. The reason for his disappearance and what happened afterwards were never clarified. His fate has inspired many books and movies, most of Italian origin, of which I haven't read or seen a single one. Thus, Magueijo's book was the first time I heard about the various theories of Majorana's disappearance, the leading ones being suicide, joining a monastery, or starting a new life in Argentina, due to depression, insanity, homosexuality or moral trouble with a research direction that Majorana might have understood earlier than everyone else would lead to the atomic bomb.

"... the [atomic] bomb, so much like a star in the sky, but so close to us that its brilliance amounted to darkness."

The more obscure theories feature various conspiracies, special forces, and/or aliens.

João's book, instead of listing all these theories, is a report on his following up on Majorana's fate. He has interviewed friends and relatives, seen the movies, read the books, visited the places. Woven together with his travels are explanations of the physics Majorana has been working on and the historical circumstances. The physics is explained on a level understandable without previous knowledge and covers atomic physics, β-decay, parity, chirality, neutrino-oscillation, (neutrinoless) double β-decay and the experiments behind all this. The reader is confronted with the difficulties scientific research had to cope with under Mussolini and Hitler, and gets to meet Majorana's contemporaries, among others Fermi, Heisenberg, Dirac and some radioactively contaminated fish.

João does not put forward his own theory or presents a solution to the mystery. Instead, he uses Majorana's life and unknown fate to get across some science and touch upon questions like the role of scientists in our societies, the clash between pragmatism and idealism, the ignorance of academics, the balance between competition and collaboration, and the influence of personal life on ones research. There's a lot in that book to make you think and João doesn't even attempt to think in your place.

The book is well written in a light-hearted style despite the dark topic, and the main flavor is sarcasm. João, let me remind you, is the one who famously suggested in his first book that the "M" in M-theory stands for "masturbation." In his book on Majorana, string theory makes an appearance as as an example for "the fad of postulating thousands of unnecessary particles," and João doesn't hesitate to speak his mind on all and everybody: Fermi, so João writes, "did lack imagination," "when [Dirac] spoke the outcome was... logically crafted insanity," and Cambridge (UK) is "that ivory tower of lunacy." The book is also interspersed with paragraphs that seem to have gotten there by random association, my favorite one is:

"Saying that we live in an odd world is often an understatement. I once had a random conversation on a Toronto street that derailed into the most sublime insanity. After a few minutes of pleasant platitudes, my casual acquaintance, out of the blue, revealed that "they" had implanted radioactive isotopes in his testicles. Being high-minded, he refrained from ejaculating, lest he might contaminate the entire universe."

and later he describes meeting an old friend at a book fair in Buenos Aires, an event that doesn't have any apparent relevance to Majorana's story. There's more side-tracks of this sort. One might say the book is also a book about João. If you decide to read it, you'll either love or hate it, but either way you'll very likely finish reading it.

“The Shape of Inner Space” is a curious mixture of Yau’s autobiography, a crash-course in differential geometry, and physics-themed popular science, sandwiched between an introduction to the history of geometry and philosophical considerations about the beauty of mathematical truth. The string that runs through the book and weaves it together are Calabi-Yau manifolds. Shing-Tung Yau, the “Yau” in “Calabi-Yau,” has spent pretty much his whole life on these manifolds and won the Fields Medal in 1982, among other achievements, for his proof of the Calabi conjecture. So the reader learns first hand from the world expert. Steve Nadis is a popular science writer, and the two have joined forces to produce the book.

The result is interesting and also courageous.

After the introduction, it follows a brief history of geometry. From Pythagoras and Plato over Euclid, Descartes, Gauss and Euler to Minkowski, Riemann, Einstein, Kaluza, Klein and, of course, Calabi. As we come closer to the 21st century, we learn about the geometrization of physics and its successes. To move on beyond Platonic solids, the reader is introduced to mathematical lingo in a rapid fire treatment. It starts with the innocent concept of derivative and integrals. From there it goes on to partial derivatives, curve integrals, non-linear partial differential equations, manifolds (differentiable, compact, orientable, product of), complex numbers, metric (in n dimensions, hermitian), parallel transport, geodesics, curvature and Ricci curvature, groups, tangent spaces, fibre bundles, exotic spheres, homeomorphic diffeomorphisms, harmonic equations, Betti numbers, Chern classes, holonomy and cohomology, Ricci flow, Riemann surfaces, Kähler manifolds and of course Calabi-Yau spaces. Just to mention a few. If you're afraid of math, this book is not for you.

In the later chapters follow the contemporary topics, and the connection to string theory is established. The reader learns about the Dirac equation, Yang-Mills theory, mirror symmetry and the Seiberg-Witten equations. We come across Yukawa-couplings, correlation functions, black hole information loss, moduli and the landscape problem. We meet familiar names like Hawking, Penrose, Guth, Strominger, Kachru, Witten, Greene, Gross, Susskind, Vafa, Giddings and more. Nadis has interviewed many researchers in the field and the text is frequently supplemented by quotations from these interviews (and other sources). One might find it an expression of laziness (or maybe cowardice) to export explanations and opinions into quotations from other people. But I found it very readable and interesting to hear the researchers’ comments and explanations of their work, and that of others, in their own words. I liked that a lot.

The mathematical and physical explanations are accomplished basically without equations (though there are a few examples) and without formal definitions. Sometimes the text is accompanied by figures that I found very helpful and well done, but figures only get you so far to understanding six dimensional spaces. Now all the used concepts are explained somewhere, and I was familiar with most of the terminology before reading the book anyway. But I suspect if you don’t know anything about field theory, differential geometry, and topology, “The Shape of Inner Space” is a very heavy read.

With use of the introduced mathematical concepts the reader then learns what Yau proved, what his colleagues proved and how the field has evolved within the last some decades. Then the authors explain how the connection to string theory came about and how this intersection of physics and math has been fruitful for both sides. That I found indeed the most interesting aspect of the book: The interrelation between mathematics and physics and the mutual benefit for both sides. Yau writes:

“[I] like to position myself at the interface between these two fields, math and physics, where a lot of interesting cross-pollination occurs. I’ve hovered around that fertile zone since the 1970s and have managed to get wind of many intriguing developments as a result.”

However, the book is very focused specifically on the cross-pollination between differential and algebraic geometry and string theory that has sprung from Calabi-Yau spaces. It is a pity there was not more about the recent and not-so-recent history of the math-physics exchange in a broader sense.

Towards the end of the book, after a somewhat bizarre interlude about the way you would die through false vacuum decay, we then find a chapter on experimental tests of string theory. Yau is a mathematician and takes the point of view of an interested outsider. His main interest is mathematical truth, and if physicists with their methods can help mathematicians discover previously unknown relationships, then what does it matter if the physics eventually turns out to be a description of reality? But one or the other reader might care.

“At the end of Dorothy’s adventures in the Land of Oz, she learned that she had the powers to get back home all along. After some decades of exploring the Land of Calabi-Yau, string theorists and their math colleagues (even those equipped with the penetrating powers of geometric analysis) are finding it hard to get back home – to the realm of everyday physics (aka the Standard Model) – and, from there, to the physics that we know must lie beyond. If only it were as easy as closing our eyes, tapping our heels together, and saying “There’s no place like home.” But then we’d miss out on all the fun.”

Unfortunately, it is not very clearly pointed out that all these tests are tests not of string theory itself but of string theory inspired phenomenological models. Finding such evidence would certainly be a boost for string theorists, but not finding it doesn’t need to bother them either. A quotation by McAllister states it very carefully correct: “It’s possible that string theory will predict a finite class of models, none of which are consistent with the observed properties of the early universe, in which case we could say the theory is excluded by observation.” Yes, it is possible. But at the moment it seems like there’s a string theory motivated model to explain whatever the data will be.

Yau and Nadis avoid commenting on the controversy about the usefulness of string theory as a description of reality. On the landscape problem Yau writes “It’s fair to say that things have gotten a little heated. I haven’t really participated in this debate, which may be one of the luxuries of being a mathematician. I don’t have to get torn up about the stuff that threatens to tear up the physics community.”

“Critical treatments of [string theory], such as The Trouble with Physics and Not Even Wrong” are mentioned in the passing, decorated with quotations from Henry Tye saying “string theory is too beautiful, rich, creative, and subtle not to be used by nature,” and Michael Atiyah letting us know that “even if we can’t measure it experimentally, [string theory] appears to have a very rich… mathematical structure. [String theorists] are onto something, obviously. Whether that something is what God’s created for the universe remains to be seen. But if He didn’t do it for the universe, it must have been for something.” (Like, maybe the multiverse?)

It then follows some elaboration on beauty and mathematical truth, and its relevance for physics:

“Of course, if beauty is going to guide us in any way […] that leaves the problem of trying to define it […] There’s no doubt that a blind adherence to mathematical beauty could lead us astray, and even when it does point us in the right direction, beauty alone can never carry us all the way to the goal line. Eventually, it has to be backed up by something […] more substantial, or our theories will never go beyond the level of informed speculation, no matter how well motivated and plausible that speculation may be.”

But Yau and Nadis remove themselves from the debate about physical relevance by focusing on the mathematics:

“Whereas the final proof in physics is in experiment, that is not the case in math… If the mathematics associated with string theory is solid and has been rigorously proven, then it will stand regardless of whether we live in a ten-dimensional universe made of strings or branes.”

And that is what the book is about – it’s a book about the mathematics of Calabi-Yau spaces, not more and not less. Just so you know what to expect should you consider buying “The Shape of Inner Space:” It’s not, in the first line, a book about string theory and certainly not about quantum gravity*. It is a book about a special kind of manifold and the interaction between physicists and mathematicians it has brought.

The book is generally well written, though I found the writing style over long stretches somewhat uninspired. Many pages it goes along the lines that soandso wrote this paper on this, and then soandso wrote a paper on that, and then a student of soandso wrote a paper on this and that, and so on. Also, I found it somewhat disturbing that in several places technical terms are used that are only introduced in later chapters, sometimes with, sometimes without, mentioning of the later explanation (metric and entropy for example). The book has a glossary, but if hadn’t known anyway what they were talking about I’d have found it a quite annoying break in the reading flow.

The book is also discontinuous in the level of explanation. Over many pages it reads almost like a review paper on Calabi-Yau spaces, summarizing who proved what when by which method. And then there comes the occasional pop-sci explanation. Just to give you an impression, here’s a quotation from a randomly chosen page (133):

“The presence of those [covariantly constant] spinors helps ensure the supersymmetry of the manifolds in question, and the demand for supersymmetry of the right sort is what pointed Strominger and Candelas to SU(3) holonomy in the first place. SU(3), in turn, is the holonomy group associated with compact, Kähler manifolds with a vanishing first Chern class and zero Ricci curvature.”

(That supersymmetry partners bosons and fermions is btw explained only some pages later.) The level of the pop sci explanations are for example that of an exchange particle mediating an interaction by the common analogy to a ball being thrown, or for quantum foam by analogy to the British railway. (“The geometry, in other words, would be undergoing shifts so violently it hardly makes sense to call it geometry. It would be like a rail system where the tracks shrink, lengthen, and curve at will –a system that would never deliver you to the right destination and, even worse, would get you there at the wrong time.”).

The impression I had was that Yau wrote a draft, and Nadis then sprinkled pop sci explanations and quotations on it.

Taken together, I enjoyed reading the book more than expected. It is a very comprehensive summary of research I have a peripheral interest in, and Yau and Nadis have presented it very nicely, so I learned some relations that previously hadn't been clear to me. I was surprised though that the AdS/CFT correspondence is only briefly mentioned and its recent applications are not discussed at all. I'd have found it relevant to the question of what string theory is a theory of. And, there's no explanation of what is actually plotted in the omnipresent pictures of Calabi-Yau spaces you find for illustration all over the place.

Reading the book I couldn't help wondering what audience it is aimed at.Readers should at the very least have read a fair share of popular physics books because they will not get an introduction to general relativity and quantum mechanics, not to mention quantum field theory, though these are essential to understanding big parts of the book. Black holes, entropy, the standard model, dark matter, inflation etc are explained with only a few sentences each. This, I will admit, was a great relieve to me because I’ve read more than enough stories about quantum pets and suicidal astronauts plunging into black holes. I’m just saying you better bring that knowledge along because otherwise you’ll miss big parts of the story. And, given the mathematical rapid fire treatment, the reader should at the very least have a high school exam, preferably a few semesters math in addition.

In summary, the book might be interesting for you if you have some, though not necessarily expert knowledge in math and physics. “The Shape of Inner Space” will give you a good impression about the state of the art, the history, and a glimpse on the possible future of research on Calabi-Yau spaces. You will learn about the interaction between math and physics it has inspired, and it will give you opportunity to ponder eternal truth and beauty in mathematics, and its relevance for Nature.* In the introduction it is made clear that “Because of our focus on so-called Calabi-Yau manifolds and their potential role in providing the geometry for the universe’s hidden dimensions – assuming such dimensions exist – this book will not explore loop quantum gravity, an alternative to string theory that does not involve extra dimensions […]” And that's the first and last time alternative approaches to quantum gravity are mentioned.

Thursday, February 03, 2011

Seed magazine has an interesting article On Science Transfer. It is about the measurement of scientific success by means of automatized metrics, a topic we have discussed several times on this blog, see eg my posts Science Metrics and Against Measure.

The mentioned article is interesting in that it focuses on measuring scientific activities that are not usually considered for academic purposes, those of communicating science and being relevant for science policies - that's what is meant with “science transfer.” To that end, commonly used measures based on citations are of limited use:

“If we want to know what scientific ideas are influencing decisions and policymaking in the public sphere or in disparate scientific fields, rather than simply the discipline in which an idea originated, citations are of less relevance [...] Writing in the popular press is equally unlikely to garner citations. Even trying to translate research into something more digestible by a lay audience within the academic publishing world is a dead end; editorial and other journalistic material is generally deemed “uncitable.”

Though it is by no means the only aspect of scientific culture responsible, the fixation on citations as a measure of scholarly impact has given scientists few reasons to communicate the value of their work to non-scientists.”

The article then discusses the possibility of more general measures of impact, based on usage, such as for example MESUR. I am skeptic that usage is an indicator for quality rather than for popularity. Some works arguably score a lot of hits and downloads exactly because they turn out to be utter nonsense.

But either way, I certainly welcome the attempt to take note of a scientist's impact on informing the public. A few days ago, Vivienne Raper had an interesting blogpost on Science Blogging and Tenuresummarizing the pros and cons of blogging next to doing research. She reports an example from innovation-country Canada:

“Cell biologist Alexander Palazzo says his blog helped him secure an assistant professorship. "My department" -- the biochemistry department at the University of Toronto in Canada -- "told me part of the reason they hired me was because of stuff I'd written on my blog," he says. "It wasn't the main reason they hired me, but it helped."”

Another item on the topic of getting science closer to the public and the role of blogging: In the last 3 months or so I received about 5 emails from freelance writers with a record of science-themed articles, asking for a guest post. As you can see I said thanks but no thanks, but I find this an interesting development. It seems there's people for who blogs represent a useful medium to earn career credits.

“Even if we erect massive databases filled with information on how scientific work is being used in real time, for the foreseeable future it seems inescapable that humans must provide oversight to derive actionable knowledge from the data. Modern weather forecasting provides an illustrative example: Copious real-time data on world weather patterns is available to anyone with a computer and an internet connection, but the vast majority of us rely on meteorologists to synthesize and analyze it to produce a daily forecast. Moreover, even more raw data and subsequent analysis are necessary to transform information about weather into knowledge about climate and how human activity has influenced it over the course of centuries.

Well-designed computer programs may be able to compile usage data on scientific discourse and publishing to generate real-time maps of scientific activity, but such maps can only inform our decision making, not replace it. A new skill set that makes use of such tools—a kind of “science meteorology”—will be necessary to serve as a bridge between the academic and public spheres.”

Granted, they are concerned with measuring the impact of scientific work on policy decisions, but I couldn't help wondering what a science meteorologist would "forecast" from data of individual scientists. This candidate is sunny with scattered papers? Clear and cold with a student chill factor of zero K? Partly cloudy with a 10% chance of tenure?

The Seed article also touches on an issue I previously commented on here:

“The problem with evaluating all [scientists] with one fast and easy evaluation system is centralization and streamlining. The more people use the same system, the more likely it becomes everybody will do the same research with the same methods.”

“I accept that metrics in some form are inevitable – after all [...] every granting or hiring committee is effectively using a metric every time they make a decision. My argument instead is essentially an argument against homogeneity in the evaluation of science: it’s not the use of metrics I’m objecting to, per se, rather it’s the idea that a relatively small number of metrics may become broadly influential. I shall argue that it’s much better if the system is very diverse, with all sorts of different ways being used to evaluate science.”

“If you have a bunch of different metrics, and they each embody different aspects of scholarly impact, I think that’s a much healthier system.”

We can agree on that. Then Bollen continues:

“People’s true value can be gleaned [...]”

Let's hope the day a scientist's “true value” is defined by a software will never come.

Summary:

Efforts are made to measure scientist's skills of communicating research to the public and policy makers. Useful for evaluating success, as defined by the measure, and for providing incentives. -- Good.

Measuring success by usage. -- Questionable.

Noting that data collection still needs human assessment. -- Good.

Diversifying in measures prevents streamlining and is thus welcome or, in other words, if you have to use metrics at least use them smartly. -- Indeed.